Is it Air/Flex SDK open source right?

I want to fix the ane file of BackendlessPN.ane, because i got an error but i didn't see any ane project in github. I test push notif on Xiaomi phone it success, but on samsung or HTC phont it got error. i though it erron in settextColor for customLayoutTitle or customLayoutDescription.

I know it is in github, but the ANE project is not provided, it only has the ANE file. so how can i fix and compile the java class so i can build the ANE? because the class inside ANE is already in jar.

I am just asking for the project source code for BackendlessPN.ane. The src in that github is just for backendless.swc.